The subject matter disclosed herein relates to a power plant and, more particularly, to a power plant having cooled fluid.
In power plants, gas turbine engine exhaust or other forms of energy (i.e., energy produced in fossil fuel burning plants, nuclear power plants, geothermal power plants and/or solar power plants) is employed to generate steam normally at one or more of high, intermediate and low pressures for a one to three pressure level heat recovery steam generator (HRSG). In the three pressure case, this steam is communicated to high, intermediate and low pressure steam turbines where the steam is used in the generation of power. While this configuration is efficient, leakage of high energy fluid from the high pressure steam turbine toward the intermediate pressure steam turbine can lead to reduced performance as the intermediate pressure steam turbine normally runs at elevated temperatures similar to the high pressure section but with increased diameters. This can result in increased mechanical stresses that may cause damage or reduction of component life. Thus, it is often necessary to cool the intermediate pressure steam turbine section by utilizing relatively cool steam from external sources.
The cooling of the leakage to eventually cool down the intermediate pressure section has been achieved by extraction of relatively cool pressurized steam from intermediate locations in the high pressure steam turbine. This solution can lead to performance losses, however, as the steam used for cooling could otherwise be used to produced useful energy output.